1. Field of the Invention
The present invention relates to a communication method for using bandwidth efficiently in Internet Protocol version 6 (IPv6), and more particularly, to a header of IPv6.
This work was supported by the IT R&D program of MIC/ETRI [2006-S-061-01, R&D on Router Technology for IPv6 based on QoS Services and Host Mobility].
2. Description of the Related Art
FIG. 1 is a conceptual diagram of a network environment in which one mobile terminal and one fixed terminal communicate.
Referring to FIG. 1, a terminal A and a terminal B communicate with each other. In FIG. 1, the terminal A is moved from 101-A position to 101-B position and is referred to as a mobile node (MN). The terminal B 102 is referred to as a correspondent node (CN). In this case, the CN 102 is in an immovable state, and is a fixed terminal or a currently immovable terminal even though it can move.
FIG. 2 is a conceptual diagram of a network environment in which two different mobile terminals communicate.
Referring to FIG. 2, the terminal A is moved from 201-A to 201-B and the terminal B is also moved from 202-A position to 202-B position. In terminal A's point of view, the terminal A itself is a MN and the terminal B is a CN. However, in terminal B's point of view, the terminal B itself is an MN and the terminal A is a CN. Therefore, in this case, the terminals A and B have both functions of MN and CN.
In a terminal, dividing a terminal into an MN and a CN is conceptual, and a terminal can be used as one node among two nodes, an MN and a CN. However, a terminal which can be used as two nodes at the same time may exist. A general mobile terminal can be designed to be used as two nodes at the same time.
In RFC 3775, which is a base specification for Mobile IPv6 and is used conventionally for supporting mobility in IPv6, even after a route optimization process between a MN and a CN is performed, a home address option of a 24 byte destination option header is additionally used for information on a home address that corresponds to an IP address of each terminal in a packet transmitted from a mobile terminal to a correspondent terminal. Also, in a packet transmitted from a correspondent terminal to a mobile terminal, a type 2 24 byte routing header is additionally used.
Therefore, if a correspondent terminal is a movable terminal, both the home address option of a destination option header and the type 2 routing header are needed for communicating between the mobile terminal and the correspondent terminal and thus a 48 byte additional header is used.
FIG. 3 is a graph illustrating overheads being generated between terminals with reference to various packet sizes, when a general mobility method of IPv6 is used in the environment as depicted in FIGS. 1 and 2.
Referring to FIG. 3, 301 is referred to as an overhead being generated during packet exchanging between a fixed terminal and a mobile terminal and 302 is referred to as an overhead being generated during packet exchanging between two different mobile terminals.
Such an additional header functions as an overhead in a wired/wireless section. In particular, problems in performance may occur in a wireless section having lower bandwidth.